Refrigerating apparatus



p H. J. SCULLEN v 2,329,139 is I REFRIGERATING APPARATUS Fi1e d Aug. 8, 1940 IVNVENTOR. qaqq uf 6:04.45!

ATTORNEY.

Patented Sept. 7, 1943 UNITED STATES PATENT OFFICE REFRIGERATIN G APPARATUS Hugh J. Scullen, Detroit, Mich, assignor to Nash-Kclvinator Corporation, Detroit, Mich, a corporation of Maryland Application August 8, 1940, Serial No. 351,811

' 7 Claims. (01. 62-8) This invention relates to refrigerating apparatus, and more particularly to refrigerating apparatus of the multiple temperature type.

One of the objects of my invention is to pro vide an improved refrigerating system of the type which includes high pressure and low pressure refrigerant evaporating portions. and arranged to cool the refrigerant passing from one section of the high pressure portion to the other section thereof by the refrigerating effect of the low pressure section.

Another object of my invention is to provide an improved refrigerating system wherein the refrigerant in the evaporating portion of the system flows through a single path, and to interpose a fixed restriction in the flow of such refrigerant so as to divide the evaporating portion of the system into a high pressure section and a low pressure section so that the low pressure section will operate at lower temperatures than the high pressure section, and to utilize the cooling effect of the low pressure section to cool the refrigerant in its passage through the high pressure section.

Another object of my invention is to utilize a portion of the low pressure section of the systern which is not required to do useful work for cooling refrigerant in its passage through the high pressure portion 50 that some of the refrigerant which is vaporized in its passage through the high pressure section is re-liquefied before it is passed entirelythrough all of the high pressure section of the system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a fragmentary view in cross section of a refrigerator embodying features of my invention; and

Fig. 2 is a diagrammatic illustration of my improved refrigerating system embodied in the refrigerator shown in Fig. 1.

Referring to the drawing, numeral 20 designates, in general, a cabinet having an inner liner 22 and an outer casing 24. The inner liner forms a food storage compartment 26. Within the food storage compartment is disposed a casing 28 which provides a freezing compartment upon the interior thereof. The casing 28 extends to the rear wall of the liner 22 and the upper ends of the casing 28 engage the top wall of the liner 22. The front part of the casing 28 may be closed by door (not shown). Within the cabinet I have disposed my refrigerating system, designated in general by the numeral 30. The system includes a condensing element 32 and heat absorbing element 34. The heat absorbing element 34 is disposed within the food storage compartment and casing 28 while the condensing element is disposed in the lower part of the cabinet in the'conventional manner. The cabinet and the installation of the system in the cabinet may be as disclosed in the co-pending application of Lawrence A. Philipp, for Refrigerating apparatus filed on even date herewith.

The refrigerant condensing element 32 includes a motor compressor unit 40 and condenser 42. Evaporated refrigerant is withdrawn from the heat absorbing element 34 through a vapor conduit 44 by the motor compressor unit 40, which compresses the refrigerant and delivers it through conduit 45 to the condenser 42 wherein it is liquefied and from which it is delivered to the heat absorbing means under the control of a small diameter tube 48 after first passing through a strainer 50. The tube 48 serves as the sole control for the flow of refrigerant from the condenser to the heat absorbing element.

The heat absorbing element 34 includes finned high pressure-high temperature portions 54 and 56 which are separated in their installation in the cabinet but are connected by a conduit 58. The refrigerant leaving the small diameter tube 48 first enters the high pressure section 54 whence it flows through conduit 58 into high pressure section 56. The refrigerant then passes through a fixed restriction 62, which may be in the form of a small diameter tube, to provide a pressure differential between the high pressure and low pressure evaporating portions. The refrigerant, after leaving the fixed restriction 62, passes into the ice making or low pressure sections 64, 66, 68 and 10. As the refrigerant must first pass through the fixed restriction 62, the pressure in the ice making sections is somewhat 1 lower than the pressure in the sections 54 and 5B. The refrigerant leaving the ice making section 10 then passes into the lower portion of an accumulator 12. The vapor return conduit 44 is connected with the upper portion of the accumulator 12 for taking gas from the accumulator 12 back to the motor compressor unit. It will be noted that the entire flow of refrigerant through the heat absorbing element is in a series circuit relation. Preferably, the fixed restriction is such that the high pressure or high temperature portions 54 and 56 function to cool the circulating air in the food storage compartment with only a slight film of frost collecting thereon during the period when the compressor is operating, and the ice making sections operate at a point well below the freezing point of ,water. Any suitable type of thermostatic element orswitch may be employed for controlling the operation of the motor compressor unit and may include a thermal bulb 86 secured to the high pressure section 54 so that the switch operates in response to changes in temperatures within the section 54.

In accordance with my invention, the system operates in a non-flooded condition, that is, liquid refrigerant is introduced into the section 54 by means of the capillary or small diameter tube 48. This refrigerant then enters section 54 and is in the form of droplets and is vaporized as it passes through the entire heat absorbing element. Consequently, only little liquid flows into the accumulator I2 as most of the liquid passing through the heat absorbing element is vaporized in its passage through said element. Since the section 54 is provided with relatively large fins, the heat absorbed by said element causes considerable vaporization in the section 54, which means that less liquid would be likely to flow into the finned heat absorbing section 56. However, I have arranged the conduit 58 so that it is in heat exchange relation with the accumulator 12 to provide for reliquefying some of the vaporized refrigerant leaving the section 54. The conduit 58 may be, if desired, soldered to the accumulator I2. Thus, liquid refrigerant in a larger quantity enters the section 56 than would be possible if it were not for the heat exchange relationship between the conduit 58 and accumulator 12.

Sections 54 and 56 are arranged on opposite sides of the casing 28 and are used primarily for cooling circulating air in the food storage compartments, whereas sections 64, 66, 68 and I6 are arranged within the casing for refrigerating a sheet metal member 90 below the freezing point of water. The sheet metal member 90 is provided with shelves 92, 94 and 96 which may be used for receiving conventional ice trays for freezing of substances therein. This ice making section of the heat absorbing element is spaced from the walls of th'e casing 29 so that the casing is not cooled below the freezing point of water so that frost does not collect thereon during operation of the motor compressor unit. Troughs 94 are positioned below the sections 54 and 56 for collecting the drip moisture from such sections. These troughs are arranged to conduct the drip water to drip receivers 96 which conduct the drip water to drip pan I positioned below the casing 28 and arranged to receive th'e drip moisture from such casing.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. Refrigerating apparatus comprising a relatively high pressure evaporating section and a relatively low pressure evaporating section connected in series with said high pressure section, said low pressure section having an accumulator at the outlet thereof in heat exchange relation with a portion of said relatively high pressure evaporating section for condensing evaporated refrigerant therein.

2. A refrigerating system comprising a refrigerant evaporating element divided into two sections, a conduit interconnecting said sections in series relation, a fixed restriction at the outlet of the second section to receive refrigerant, and a second refrigerant evaporating element connected to said fixed restriction and having an accumulation at the outlet thereof in heat exchange relation to said conduit for condensing evaporated refrigerant therein.

3. A refrigerating system comprising a refrigerant evaporating element divided into two sections, a conduit interconnecting said sections in series relation, a fixed restriction at the outlet of the second section to receive refrigerant, and a second refrigerant evaporating element connected to said fixed restriction and having an accumulator in heat exchange relation with said conduit.

4. A refrigerating system comprising a plurality of serpentine non-flooded refrigerant evaporating sections, conduits interconnecting said sections in series relation, and an accumulating element at the outlet of one of said sections arranged in heat exchange relation with at least one of said interconnecting conduits for refrigerating said conduit below the temperature of the sections connected th'ereby.

5. A refrigerating system comprising a nonflooded refrigerant evaporating conduit and an accumulator at the outlet thereof arranged in heat exchange relation with an intermediate portion of said evaporating conduit for refrigerating said portion below the temperature of adjacent portions.

6. A refrigerating system comprising a nonflooded refrigerant evaporating conduit and means at the outlet of said conduit for receiving unevaporated refrigerant therefrom, said means being arranged in heat exchange relation with an intermediate portion of said evaporating conduit for enhancing the heat transfer characteristics of said conduit.

7. The combination of an evaporator and an accumulator, said accumulator having an outlet for vaporized refrigerant and said evaporator comprising a continuous coil having an intermediate portion disposed in heat exchange relation with said accumulator and having its outlet end terminating in said accumulator in spaced 

